Cardiac disease and stroke pearls

from Continuum based on vascular boards review

1. One percent of acute strokes are complicated by coexisting acute MI
2. Treatment issues: STEMI (ST Elevation MI) and Unstable Angina/non STEMI(UA/NSTEMI) are treated differently. The former group contains Q wave MI patients or candidates for; the latter group contains non MI patients and non Q wave MI patients. Differentiate with troponins. Only the first group gets alteplase or acute cath, latter group may get later? cath. ASA 81-162 is always indicated, clopidogrel in suggested in UA/NSTEMI for 12 months based on CURE study (Clopidogrel in Unstable angina to prevent Recurrent iscemic Events). In STEMI clopidogrel is suggested only for those unable to tolerate aspirin or those who receive a stent.
3. Warfarin indications include alternative to aspirin for secondary prevention in aspirin intolerant; addition to asa in post MI or ACS, mural thrombus, or af; as short tern addition to ASA and clopidogrel in a post MI patient with a stent who also has an indication for anticoagulation. In this case, clopidogrel therapy is limited to 1 month for bare metal stents, 3-6 months after coated stents.
4. The use of dipyridamole in patients with stable angina, is problematic due to vasodilatation. ACC/AHA cautions against, although the ESPS II trial did not indicate such.
Summary-- patients may need dual/triple therapy; patients with combined treatment may have been left on dual therapy too long and may need reduction to monotherapy; warfarin after an ACS is added to, does not replace ASA.


Other pearls
1. Andersen et al. suggested that fewer strokes occur with atrial rather than ventricular based pacing; a question exists abotu identifying AF in paced patients due to pacer artefact. In not completely accepted. Temporary pacer reprogramming to low ventricular response rate can sort out underlying rhythm.
2. MOST trial (MOde Selection Trial in sinus node dysfunction) showed atrial high rate events esp. bpm>220 for >10 consecutive beat signal risk of stroke and death. Atrial high rate events showed twice the risk of death and six times risk of AF.
3. Pacer insertion is associated with a one year risk of AF of 10 % and 2 year risk of 11 % in patients not with history. No difference based on reason for pacer insertion (AV node dysfunction v. SSS). Stroke risk is higher though in patients paced for SSS or AV Neurologist role is " insure underlying rhythm evaluation is performed"
4. 25-40 % of stroke patients have known IHD, another 25 % have silent disease
5. Early cardiac death (first 30days) occurs in 1 percent of ischemic stroke patients; in next two years, risk of another stroke is 3-4 times risk of MI; risk of MI reaches parity at abot 5 years.

HAT score to predict hemorrhage after alteplase

The Hat Score A simple grading sclae for predicting hemorrhage after thrombolysis


Lou M et al. Risk stratification measure to predict hemorrhage after alteplase given for stroke. Collective rate of symptomatic ICH is two percent (0 points); 5 % (1 point), 10 % (2 points), 15 % (3 points), 44 % (>3 points).

diabetes-- 1 point for history of DM or entry glc > 200
pretreatment NIHSS score-- 1 point if 15-20, 2 points if > 20
presence of easily visible hypodensity on initial head CT-- 1 point if yes but <> 1/3 of MCA territory

Continuum CVA risk factors: Behavioral: cigarrette

Cigarette smoking is an independent risk factors that is DOSE DEPENDENT (Gorelick, 1989). A meta-analysis found a rr of cigarettes was 1.5 (Shinton,Beevers 1989) . Passive exposure to smoke increased the progression of atherosclerosis (Howard et al 1998). By stroke subtype, rr is, ICH .74; ischemic stroke 1.92; SAH 2.93. Dose dependent: rr of <10 20 ="1.82." 74=" 1.75;">60 grams/da leads ot rr of 1.64. , hem stroke is 2.18. Less than 12 grams/day shows rr of .8.

Physical activity -1994 Behavioral risk factor surveillance shows increased physical activity lowers stroke risk. Northern Manhattan Study showed physical activity led to 63 % reduction of risk of recurrent stroke. Both exercise intensity and duration is key. Suggest 30 minutes per day of moderate activity.

Diet results conflicting . However moderately increased homocysteine in a risk factor for stroke. However, Vitamin in stroke trial showed no benefit of treatment with b6 b12 and folate. FRUIT and vegetable increased intake lowers stroke risk. Cruciferous and green leafy vegetable and citrus protects against ischemic stroke more. May be due to antioxidants. Milk, calcium, cereal fiber, and fish consumption and carotenoids may be helpful. Limited saturated fat consumption may be important.

Abdominal obesity is an independent risk factor. Men with waist-hip ratios of more than 0.93 and women above .86 have more stroke especially in younger patients. FFA (free fatty acids) and TNF alpha lead to insulin resistance.

Other nontraditional risk factors for stroke are mitral annular calcification, mitral valve prolapse, aortic arch atherosclerosis, PFO, exogenous estrogens, chronic infections, migraine and hypercoagulable state.

Continuum CVA risk factors:TIA DM lipids

TIA-- annual stroke risk is 1-15 %. In hospital referred, annual risk of stroke, MI or death was 75. % (Hankey 1991). Amaurosis not as bad. 10 % of those with TIA got stroke and 25 % an AE within 90 days. HALF THE PATIENTS WITH STROKE DEVELOPED STROKE WITHIN 2 DAYS OF TIA. Risk factors for stroke after tia included age, duration > 10 minutes, dm, weakness, speech impairment.

Diabestes has an independent effect on stroke demonstrated in the Honolulu heart program (2x risk) and a large population based study of 14,000 found fbs>140 was associated with rr of stroke of 2.26 after adjusting for other risk factors Folsom et al. 1999). One study found a greater effect among women with stroke. Attributable risk of stroke to diabetes was higher in N Manhattan Stroke study due to 22 % prevalence of dm. Insulin resistance was associated with 1.19 rr of cva (Folsom 1999). ADA now classifies fbs>110 as diabetic, aqnd 100-109 as prediabetic.

LIPIDS- increased TG, total cholesterol and LDL are risk factors. For LDL relation to stroke is "less clear" than for IHD with mixed study results. One large meta-analysis of 450,000 found no relation to stroke. By subtype, large artery disease may be more related to cholesterol. HDL may be protective per N Manhattan Stroke Study with higher HDL helping elderly. Statins help.

Continuum CVA risk factors: carotid as. + CAD

CAD confers 2 x risk of stroke, with LVH is 3x risk, chf is 4x risk. The attributable risk of CAD is 12 % and ranges from 2.3-6 % for CHF. Post MI stroke risk over five years is 8.1 percent, higher in older patients, in pts with ef< 28 % (rr 1.86).

Symptomatic carotid stenosis confers 26 % risk of recurrent stroke with medical treatment after tia/minor stroke over ? time, and asymptomatic stenosis risk is 1.3 % annually if stenosis is <75> 3.3 %. (Norris 1991). The combined tia/stroke risk is 10.5 % per year with >75 % stenosis(????). ACAS randomized 1662 patients. Angio risk was 1.2 % and perioperative risk was 2.3 %. After median followup of 2.7 years, study was stopped due to benefit ( 11 % of those with medical treatment had stroke ipsilateral, whereas surgical + medical had 5 % ipsilateral stroke, perioperative stroke or death in five years, 55% risk reduction). More benefit among men, no effect of degree of stenosis. Halliday et al, 2004, showed in another trial that in patients <75 with severe carotid stenosis, the stroke risk in the surgery deferred group was similar to that seen in ACAS. Medical group risk was 11 %, in immediate surgery group was 3.8 % at five years, Perioperative risk of stroke/death was 3.1 % effect equal in gender groups.